Notifications can be silenced from System Preferences > Notifications by turning on Do Not Disturb. I have another problem with the notifications. They are displayed in the upper right corner where it constantly interferes with my actions. Does anybody know a way to move these to the lower right corner that I rarely use.
I turned on do not disturb 0:00 to 23:59 but am still getting them. I think there are different types of notifications.
In Mavericks there was a way to disable the process in terminal but it's not working on Yosemite. I also don't like the icon there instead of spotlight.